I really don't know why I would want to take on the task of starting over again but I may have an opportunity to do so. I have a friend who is looking for a used Link. I could sell him my link for enough money to buy an MSPNP. My current setup:
T25/28 @ 13-15 PSI
550 injectors with resistors
DO WI
LC-1 WB
No plans for further upgrades

What advantages of MSPNP attract you the most and what will you use compared to what the link doens't offer.
EBC, Launch, Knock, possible WI control someday maybe. Very complete datalogs.
I don't know anything about the link but what does the MSPNP do that makes you want it? I personally feel the link is dying, MS is going to be around a long time, and if you have the chance to upgrade, why not. It'll be more work on your part but it might be worth it in the long run.

OTOH, Link might run with less little hiccups as it was designed and built by a company that is experienced building race ecus and has probably knows a lot of the little secrets involved with making everything run right. Thats just my opinion and its worth a grain of salt.